(B.) - Paper by the Author On the Action of Pancreatine upon Fat, and the Proper Form in which to use it. (Reprinted from the British Medical Journal, November 27, 1880.)

I have watched with much satisfaction the reinforcement, under the flag of Dr. W. Roberts, of the interest in the medical use of pancreatic preparations, first excited by my papers in 1864-6; and, hoping that nothing but good could come of Dr. Roberts' campaign, I have hitherto abstained from intermeddling.

After carefully restudying Dr. Roberts' contributions, however, I find myself, at last, constrained to come forward, to prevent more harm from being done by one part of his statements, than would be compensated for by all the good that could accrue from the rest. He has done excellent service by bringing prominently forward his experiments, confirmatory of the wonderful effects of the pancreatic secretion in digesting starch and albuminoids, and especially in formulating his results in the very useful recipe for "peptonised (pancreatised) milk gruel," which seems somehow or other to have fascinated the professional mind more strongly than the forms for - pancreatised suet and milk; pancreatised milk, egg, and arrowroot; pancreatised milk-cocoa; and pancreatised nutritive enemata, published by me from time to time (1870, 1872, 1875, 1878, 1880). (See Special Recipes)

But it must be remembered that, while we have excellent means of digesting albuminoids and starch in pepsine and vegetable diatase, and, therefore, are not thrown upon the pancreas for these purposes for want of any other agent, this is not the case with regard to the emulsification (digestion) of fat by the pancreatic method. Here we are left entirely destitute if deprived of pancreatic action. There is no other known means of arriving at the same sort of emulsification of fat as that produced by pancreatisation. Yet it is this special action of the pancreas on fats - so far the most precious of its powers - that Dr. Roberts disposes of, as though it were of the least importance to medical practice, in the following passage: - " I have not had an opportunity of examining the behaviour of pancreatic juice with fatty matter, and cannot, therefore, speak of its properties; but it is singular, if, as alleged, the effect of pancreatic juice and pancreatic tissue on fat is due to the presence of a soluble ferment, that the extracts of pancreas possess none of the same power.....I could not satisfy myself that any of these extracts possessed any special power of emulsifying fat." (Lumleian Lectures.)

No one who has experimented much with the pancreas will be surprised that an experimenter should be so charmed by the almost miraculous celerity and completeness of its amylolytic and proteolytic action as to be in danger of neglecting the other properties of the secretion. But the emulsifying power of the pancreas is so remarkable, so unmistakable, and so important, that I am certainly astonished at Dr. Roberts' statement.

I hope shortly to publish my private journal and correspondence relating to the experiments made by me, and for me, since 1863; but in the meantime I append to this article a few extracts from them, plainly showing the effect of the pancreas and of pancreatine on fat.

Since the first experiments were made by Mr. Heathorn and myself in 1863, hundreds of thousands of pounds of fat have been made into pancreatic emulsion, simply by the action of the pancreas. There is no gainsaying this practical demonstration of the power of the pancreas to emulsify fat.

But it does not therefore follow that pancreatic extracts, essences, and liquors have the same power; and what I wish most conspicuously to bring before the profession is, that Dr. Roberts is quite right in stating that they have not. These fluid extracts, essences, and liquors of pancreas were all tried by me years ago, and rejected as useless on this very account. They possess the amylolytic and proteolytic properties - which are easily obtained, and are convenient and useful for the digestion of starch and albumen - like pepsin and vegetable diastase; but they do not, in a sufficient degree to be valuable, possess the peculiar special property of the pancreas, that which no other substance at present known possesses, viz., the power of converting fat without saponification into a true permanent emulsion, capable of admixture with water; the property which I described and demonstrated to the Royal Society in 1868, and which was referred to by Dr. Letheby in his Cantor Lectures at the Society of Arts, shortly afterwards, as follows: -

"More than twenty years ago, Bernard proved what Valentin had long before suspected, that pancreatic fluid was concerned in the digestion of fatty matters; but he fell into error in supposing that its action was to saponify the fat and to set free the glycerine. Here is a specimen of glycerine and of lead soap obtained from the fat upon which the pancreatic fluid had previously acted, showing that saponification had not been effected. The true action of the pancreatic secretion is, evidently, to break up the large granules and crystals, and globules of oil and fat, into myriads of minute particles of from the l-3000th to l-15000th of an inch in diameter. In this way, the fat is emulsified and converted into a milky fluid, which mixes freely with water. We are indebted for this knowledge to Dr. Dobell. When the fresh pancreas (that of the pig) is rubbed down in a mortar with twice its weight of hog's lard, it rapidly emulsifies it."

Dr. Roberts speaks of its being "alleged" that this "effect of pancreatic juice and pancreatic tissue on fat is due to the presence of a soluble ferment;" but he does not say who alleges this. In the introduction to my book on Tuberculosis, in 1866, I said, "We found that there are several active principles of the pancreatic secretion all essential to its proper functions. There is no one of these taken singly which completely represents the true properties of the healthy pancreatic juice;" and in my paper to the Royal Society, in 1868, I stated that up to that time "all attempts to isolate the several properties of the pancreas into separate products had failed - no one of such products having been found to possess in perfection the property of acting upon fat in the manner described in this paper as peculiar to the pancreas. By the term 'pancreatine,' therefore, I desire to represent the entire properties of the pancreas in a convenient form for keeping, for experiment and for administration as a remedial agent." The only preparation with which I am acquainted, which answers to this description is the pancreatine powder of Savory & Moore - practically, powdered pancreas. This was the outcome of the experiments made for me by Mr. Heathorn and Mr.

Schweitzer; and it cannot be too emphatically stated that when the object is to assist in the digestion and assimilation of fat, the liquid pancreatines must be rejected, and no other preparation used except the pancreatine powder.

Extracts from Private Journal on Experiments made for me, and by me, with Pancreas and Pancreatine.

September, 1863. - "To prepare pancreatic emulsion, take the pancreas of the pig immediately after its removal from the body, and, after separating all external suet, dissect out the lobes, of which the pancreas is composed, avoiding, as far as possible, the rupture of the ducts which intercommunicate with them. The pancreas, so dissected, will probably weigh about 1 oz. avoirdupois. This is to be well pounded in a mortar, and 1 1/2 oz. of tepid distilled water added. Set aside to infuse in a water oven for 30 minutes, at temperature 100°; on removal, strain through muslin, and while still warm, mix with oil or fat in a fluid state, either by agitation in a bottle or trituration in a mortar." - (Signed) A. Heathorn.

To this I noted that "the emulsion so made, under a 1/4 inch object-glass, appears peculiarly equal, the oil globules being less than half the size of a blood corpuscle. This emulsion, treated with pepsin and hydrochloric acid and water, remained complete two days after such mixture."

September, 1864. - "The emulsion with lard oil (made by the same process, is satisfactory. It is a far more elegant pharmaceutical preparation than our former emulsion of beef fat." - (Signed) A. Heathorn.

August 23, 1864. - "The total amount of emulsion consumed by the patients of the Royal Hospital amounts to 156 lbs. avoirdupois, requiring 468 pancreases to emulsify the fat. The 33 patients consumed 105 lbs., requiring 315 pancreases to emulsify the fat." - (Signed) A. Heathorn.

October 29, 1864. - " I have recently succeeded in obtaining from the pancreas some of the secretion - viz., pancreatic fluid. It possesses very active properties in emulsifying oil, and is, I think, one more proof of the reality of the pancreatic emulsion. The specimen I have preserved for your examination." - (Signed) A. HeatHorn.

July 24, 1867. - Specimens of pancreatine and pancreatic emulsion were exhibited at the Royal College of Physicians at my request, and after the exhibition Mr. Julius Schweitzer wrote, July 27, 1867: "I made this specimen of pancreatine on purpose for you. It will digest sixteen times its own weight of lard. For carrying out the experiment, I take, say, 1 grain of pancreatine, rub it up in a mortar, with about 2 drachms of distilled water, and add 16 grains of lard, and mix the whole. I stir it together occasionally, till I find that the water has been absorbed, when I add a little more water, and, as before, stir it occasionally. It is best to commence this experiment in the evening, and to leave the mixture undisturbed all night; next morning the pancreatine will be found to have acted on the lard, the mixture readily mixing with water; and the above quantities will require about 3 oz. of water to form a smooth thick creamy emulsion. This emulsion still possesses the power to destroy the blue reaction of starch-paste, made of two grains of starch and 3 or 4 oz. of boiling water. By itself, one part of this pancreatine destroys the blue reaction of starch-paste made of eight times its weight of dry starch. The pancreatine does not decompose lard, it seems solely to alter the molecular conditions, adding perhaps, a little water, but rendering the single minute globules, into which it splits up the fat, able to suspend and emulsify the water. The glycerine is still left in the fat, and can be extracted from the first crude emulsion by means of ether, and combining it with oxide of lead. This pancreatine also acts on albumen, but the extent of its action I have not yet ascertained. All these experiments are made at the suggestion of Dr. Dobell." - (Signed) Julius Schweitzer.

On the next day, July 28, Mr. Schweitzer wrote to me: - "I tried the experiment of digesting white of egg, boiled hard, with pancreatine. I took one part of pancreatine and 20 parts of boiled white of egg. 1 found that this was somewhat too much, but at a rough guess I should say that it dissolved about 16 or 17 parts of the coagulated white of egg. It is a curious coincidence that one part of pancreatine emulsifies 16 parts of lard, digests 17 parts of dry starch, made into paste, and 16 parts of boiled white of egg."

October 6, 1868. - The pancreatine exhibited at the Royal Society to illustrate your paper (December 12, 1867) is exactly the same as what is sold to-day. It, is perfectly good, and possesses the same properties now as then. Pancreatine is a very wonderful thing, and not half understood or appreciated at present." - (Signed) Julius Schweitzer.