Taking the average of these five instances as a sample of the effect of a vegetable diet on the liver of the dog, it appears that the organ rather more than equals in ounces the number of pounds the animal weighs. It will be remembered that, after an animal diet, the average given was rather under the half ounce to the pound. The facts as to the amount of amyloid substance stand thus :

No analyses were made of the livers of the dogs Nos. 12 and 13, but the quantity of amyloid substance was unusually large. It was whilst examining these livers for the determination of sugar that I was first led to notice the effect of a vegetable diet that I am now describing.

Amount of Amyloid Substance in the Liver, yielded by the foregoing examples upon a Diet of Vegetable Food.

Average amount of amyloid substance yielded by the above

three analyses 17.23 per cent.

* This liver was not examined till an hour and a half after death.

THE LIVER OF THE DOG UNDER A DIET OF ANIMAL FOOD, WITH AN ADMIXTURE OF SUGAR.

The effect of giving an admixture of sugar with animal food is similar to that produced by a vegetable diet. The sugar employed in my experiments was the brown or moist sugar that is used for domestic purposes. Various devices had to be resorted to, to get the animal to take it. The plan I found to succeed the best was to introduce it into short lengths of the intestinal tube forming part of the bundle of tripe. I will give the leading particulars belonging to each of the four dogs that formed the subjects of experiment in this way.

No. 17. A nearly full-grown mongrel dog, kept for eight days on a diet consisting of sugar and a bundle of tripe per diem. At first, one-third of a pound of sugar was administered daily, but after three or four days, the animal showed a disinclination for food, vomited, and had bilious diarrhoea. The quantity of sugar was reduced to a quarter of a pound daily. The dog now devoured voraciously all that was given to it. The urine collected from the bladder after death gave a strong reaction of sugar (grape-sugar).

No. 18. A youngish dog, fed for nine days on a bundle of tripe and a quarter of a pound of sugar daily. It consumed its food well at first, but during the last few days a great amount of coaxing was required to get it to take its full allowance. There was scarcely any urine to be procured from the bladder after death; what there was, gave no saccharine reaction.

No. 19. A middle-aged dog, kept for eight days on a bundle of tripe and a quarter of a pound of sugar daily. The urine at death gave a slight but decided reaction of sugar.

No. 20. A dog not quite full grown. Fed for five days on the same diet as the preceding dog. The urine collected after death gave a strong reaction of sugar.

The following are the results of the examination made in these cases—

The average yielded by these four dogs, thus gives a relative weight of liver, bearing a close approximation to that obtained after a diet of vegetable food; in the one case being as 1 to 16, in the other as 1 to 15. The amount of amyloid substance in each example was large, as is shown by the following results of analysis:

Amount of Amyloid Substance in the Liver yielded by the foregoing examples upon a Diet of Animal Food and Sugar.

Average amount of amyloid substance yielded by the above four analyses 14.5 per cent.

Besides these above-mentioned effects upon the liver which resulted from the admixture of sugar with animal food, the organ likewise presented an alteration in

its physical appearance. Under a purely animal diet, it was comparatively firm and fleshy, requiring considerable force to break it down between the fingers. Under the animal diet with sugar, it became exceedingly soft, and was readily crushed by a very slight pressure. It looked swollen and flabby and was pale in colour. The bile I noticed, too, was of a much paler yellow than after a strictly animal diet.

There was another fact, that, in each case, I was struck with, on making the examination after the diet of sugar and animal food. Peyer's patches and the solitary glands of the intestine, especially those of the cæcum, presented a prominence and an appearance of vascularity that conspicuously excited my attention.

In three out of the four examples, as mentioned in the particulars, the allowance of sugar that was given, communicated to the urine a saccharine quality. It is worthy of note, that, although cane-sugar was ingested, it was grape-sugar that was detected in the urine.

The conclusion to be drawn from the observations I have made upon the rabbit in reference to the state of its liver is, that the better the condition of the animal, the larger is the quantity of amyloid substance that the organ contains. The condition in which most of the London rabbits are sold is not one from which, there is reason to conclude, a fair estimate can be made of the relative size of the liver and proportion of amyloid substance belonging to the perfectly healthy and vigorous state; for, according to my experience, it is quite the exception on opening the abdomen, not to meet with a liver, more or less pervaded with entozoa. Subjoined, however, are the results of four examinations, the rabbits having been kept upon their usual food, and having presented about an ordinary appearance as regards health and condition :

When looking at the relative weight of the liver in the rabbit, it must not be left out of consideration, how large a quantity of perfectly extraneous matter is estimated with the weight of the animal. The intestinal canal is exceedingly long, and the contents, especially of the stomach and the very large cæcum, exceedingly bulky. The stomach and intestine, in fact, with their contents, in two instances that I specially examined, were found to equal the 1-5th and the 1-5th part of the weight of the body. In the dog, the proportion is very much less. In one dog that had been kept on a vegetable diet, the alimentary canal and its contents formed about the 1-8th part of the weight of the animal; whilst, in another that had been well fed on an animal diet, the proportion was only the 1-10th.

I have conducted experiments on rabbits, in which, instead of allowing them their ordinary food, I have kept them for a few days on a mixture of starch and sugar only. Other rabbits were kept fasting for the sake of having a comparison. In these experiments, the effect produced on the liver by the administration of the starch and sugar is strikingly corroborative of the results obtained upon the dog, under the influence of different diets.

In one experiment, a couple of full-grown rabbits were taken as nearly as possible resembling each other. One was kept fasting, whilst the other was fed daily for three days, through a tube passed down the œsophagus into the stomach, with one ounce of starch and three-quarters of an ounce of